NAME

SYNOPSIS

DESCRIPTION

The fcoemon daemon is the core component of the Open-FCoE management service.
The primary function of fcoemon is to control FCoE instances. fcoemon will create,
destroy, reset, enable and disable FCoE instances based on system configuration,
administrative commands, and runtime events.
On startup, fcoemon will create FCoE instances defined by the configuration files (see
FILES section below). Since FCoE typically relies on the Data Center Bridging (DCB)
capabilities of an Ethernet interface, fcoemon establishes a connection with the LLDP
daemon lldpad to query the status of the DCB features on relevant Ethernet interfaces and
receive DCB configuration change events.
During runtime, fcoemon will monitor network and lldpad events for the relevant Ethernet
interfaces and perform appropriate actions (create, destroy, enable, disable) on the FCoE
instances. fcoemon also provides a client interface via which the fcoeadm utility is able
to issue commands.
Installation of the fcoe-utils package will set up an fcoe service which will control the
execution of the fcoemon daemon.

OPTIONS

-f, --foreground
Run fcoemon in the foreground.
-d, --debug
Enable debugging messages.
-l, --legacy
Force fcoemon to use the legacy /sys/modlue/libfcoe/parameters/ interface. The default
is to use the newer /sys/bus/fcoe/ interfaces if they are available.
-s, --syslog
Use syslogd for logging. The default behavior is to log to stdout and stderr.
-h, --help
Show help message with basic usage instructions
-v, --version
Show the version of the fcoemon command.

TERMINOLOGY

DCB
Data Center Bridging A set of Ethernet enhancement standards developed by the IEEE
802.1 Working Group.
See http://www.ieee802.org/1/pages/dcbridges.html for more information.
DCBX
DCB Capabilities Exchange Protocol, implemented by the DCB module of lldpad. DCBX
exchanges DCB capabilities and configuration with a link partner as a series of values
transferred using the Link Layer Discovery Protocol (LLDP).
PFC
Priority-based Flow Control, a DCB feature.
App:FCoE
The FCoE instance of application specific parameters in DCBX.

CRITERIAUSEDFORCONTROLLINGTHEFCOEINSTANCE

fcoemon uses two information sources for determining when to create an FCoE instance: the
state of the network interface, which may be a VLAN interface, and, if required for the
FCoE instance, the state of the DCB configuration on the physical Ethernet interface.
First of all, the network interface must be "up" for the FCoE instance to be created.
Secondly, if the FCoE configuration indicates that DCB is required, then the following
criteria must be satisfied before the FCoE interface is created:
· DCB is enabled on the Ethernet interface.
· The PFC DCB feature is enabled and operational.
· The App:FCoE DCB feature is enabled and operational.
· The priority indicated by the App:FCoE feature is also enabled for PFC.
Once the FCoE instance is created by fcoemon, it will only be destroyed under the
following conditions:
· The driver for the Ethernet interface is unloaded.
· A user administratively destroys the FCoE instance using fcoeadm.
· The fcoemon daemon is terminated.
If DCB is required for the FCoE instance, and the DCB settings change after the interface
is created, the following criteria are used to disable the FCoE instance:
· DCB is disabled on the Ethernet interface.
· The App:FCoE DCB feature is not enabled.
· The App:FCoE and PFC features are operational AND the priority indicated by App:FCoE
is not enabled for PFC.
Otherwise, the FCoE instance will always remain enabled.

CONFIGURATION

Once the fcoe-utils and lldpad packages have been installed and the corresponding services
are running, there are a few simple configuration steps required to get an FCoE instance
up and running. The following assumes that DCB will be required for the interface.
· Ensure that the configuration on the peer device (e.g. FCoE capable switch) has the
necessary configurations (VLANs, DCB, DCBX).
· Configure any needed VLAN interfaces on the local system.
· Create and configure /etc/fcoe/cfg-<ifname> files for the network interfaces over
which FCoE instances need to be created. See the FILES sections for details. Note that
ifname may be for a VLAN interface.
· Restart the fcoe service (i.e. fcoemon).
· The default DCB configuration of an Ethernet interface managed by lldpad requires the
following configuration using dcbtool.
dcbtool sc ethX dcb on <-- enable DCB on the interface
dcbtool sc ethX app:fcoe e:1 <-- enable App:FCoE on the interface
These steps only need to be done one time. Note that if other DCB configuration changes
have been made with dcbtool, then additional changes may need to be made in order to
satisfy the DCB criteria for creating an FCoE instance. Consult dcbtool for details.
Once these configuration steps have been performed, use fcoeadm to query the status of the
FCoE instances.

FILES

/etc/fcoe/config
This is the primary configuration file for the fcoe system service. The default options in
this file are: DEBUG="no" and USE_SYSLOG="yes". The former is used to enable debugging
messages from the fcoe service script and fcoemon (via the --debug option). The latter is
to indicate if the log messages are to be output to the system log (via the --syslog
option). SUPPORTED_DRIVERS is the list of drivers to automatically load during fcoe
service start. Any changes to this file will require a restart of the fcoe service.
/etc/fcoe/cfg-<ifname>
These files are read by fcoemon on initialization. They are used to indicate which
Ethernet or VLAN interfaces should have FCoE instances created. The option values in this
file normally are: FCOE_ENABLE="yes", DCB_REQUIRED="yes", and AUTO_VLAN="yes", though if
the variable values are omitted, they default to "no".
FCOE_ENABLE
is used to enable/disable creation of the FCoE instance. If FCoE_ENABLE is set to
"no", then the other configuration values have no effect.
DCB_REQUIRED
indicates if the DCB service is required on the Ethernet interface.
AUTO_VLAN
indicates if VLAN discovery should be performed. If AUTO_VLAN is set to "yes", then
once the link configuration has been validated, fcoemon will run run the FIP VLAN
discovery protocol on the Ethernet interface. Network interfaces for any discovered
FCoE VLANs will be automatically created, if they are not already configured, and FCoE
instances will be created on the VLAN interfaces. If the network interface specified
by the filename is already a VLAN interface, the AUTO_VLAN setting is ignored.
MODE
indicates whether operation will be in fabric or vn2vn mode. The default is fabric.
FIP_RESP
indicates whether a FIP responder should be activated on this device to support VLAN
discovery in a vn2vn environment. The default is "no". Often this will be used on a
vn2vn node also serving as a target. When using this option, the AUTO_VLAN should not
be set and the supported VLANs should have configuration files supplied, constituting
a static VLAN configuration that provides the information for the FIP responder to
return. This should be set on a base device, which should probably have FCOE_ENABLE
set to "no" since presumably FCoE operation will be on the configured VLANs.
Note that the attached Ethernet peer device (e.g. FCoE capable switch port) must have
compatible settings For DCB and FCoE to function properly.
/etc/init.d/fcoe
This is the fcoe system service script. This script is invoked by the init process or by
the service command to start and stop the fcoemon. On systemd-enabled systems, fcoemon is
controlled via the fcoe.service unit.

VLANNAMINGCONVENTIONS

If a new VLAN device is created (see the description of the AUTO_VLAN setting above), it
will have the name dev.vlan-fcoe; where dev is the name of the Ethernet parent device and
vlan is the discovered VLAN ID number.